1. Field of the Invention
The present invention relates to a composition comprising Aralia extracts for the prevention and treatment of cataract. In particular, the present invention relates to a composition for prevention or treatment of cataract comprising solvent extracts of Aralia, wherein said solvent is ethanol, methanol or a mixture thereof. Also, the present invention relates to a process for preparing a composition for prevention and treatment of cataract, wherein the process comprises the following steps of: a) extracting Aralia with alcohol; b) filtrating the extract obtained from step a) to give a residue and a filtrate; and c) removing the alcohol from the filtrate obtained from step b) to give a powder.
2. Description of the Prior Art
Cataract is a disease caused by the degeneration of lenses due to aging. Although this disease may occur naturally, the frequency of occurrence is highest in diabetic patients with complications.
According to a survey performed by the National Statistical Office of Korea on the leading causes of death in 1991, diabetes ranked 6th, accounting for 2.8% of all deaths in Korea (National Statistical Office, 1992). Diabetes often leads to fatality due to complications resulting from high blood glucose levels. A high level of blood glucose exposure in the body for 15 to 20 years damages several organs due to the disturbance in energy metabolism. Thus, chronic diabetic complications, such as diabetic cataract, diabetic nephropathy, diabetic peripheral nerve disorder, diabetic hyperlipemia, etc., often occur. (Vlassara H. (1990), Chronic diabetic complications and tissue glycosylation, Diabetes Care 13(11): 1180-1185) Patients with diabetes have a 25 times higher risk of blindness, 20 times higher risk of kidney failure, and 2-6 times higher risk of coronary cardiac disorders, in comparison with a normal person.
Cataract is a major cause of blindness, since approximately 35% of all cases of blindness are caused by cataract. (Chylack L. T. (1984), Mechanism of Senile Cataract Formation, Ophtalmol. 91: 596-602) Cataract is found in more than 50% of people in their sixties, more than 60% of people in their seventies, and more than 70% of people in their eighties. Patients with diabetes often develop cataract in their forties or fifties. Thus, vision is deteriorated and weakened at a high rate. In particular, cataract may occur in those patients who are in their twenties or thirties when they have insulin-dependent diabetes. Cataract is a visual disorder that is caused when light cannot reach the retina due to cloudiness of the lens. This disease can be treated by implanting an artificial lens through surgery. However, after surgery, patients"" eyes may be inflamed, or healing of the wound may be delayed due to diabetes. In addition, patients are more apt to bleed. Especially, there are many cases where cataract caused by insulin-dependent diabetes progresses to after-cataract, which mean that vision regained after surgery is lost again. (In addition, patients are more apt to bleed, and the vision regained by surgery might be lost again.)
Existing aldose reductase inhibitors that were developed as a therapeutic agent for diabetic complications are not currently in use because of their side effects. Recently, in an attempt to develop medicines that overcome such side effects and are more effective, research for the synthesis of an aldose reductase inhibitor has been performed by further looking into the relationship between the structure and the activity of the aldose reductase inhibitor and determining the characteristical structure that has higher activity and can function continuously. (Potier N., Barth P., Tritsch D., Biellmann J-F. and Van Dorsselaer A. (1997), Study of non-covalent enzyme inhibitor complexes of aldose reductase by electrospray mass spectrometry, Eur. J Biochem. 243: 274-282).
There have been active research activities for effective aldose reductase inhibition using flavonoid components that are extracted from the root of Scutelladose reductaseia baicalensis. Many anti-oxidant materials, such as vitamin C, vitamin E, glutathione, catalin, baineiting, catachrome-OFTAN, Vita-iodurol, quinax, etc., are currently known as medicines for cataract. (Chasovnikova L. V., Formazyuk V. E., Sergienko V. I., Boldrev A. A., and Severin S. E. (1990), The antioxidative properties of carnosine and other drugs. Biochem. International 20(6): 1097-1103).
Catalin is also used as a therapeutic agent for cataract. However, such medication cannot cure the degenerated lens protein completely. Thus, catalin is not actually valuable. Currently, the treatment for cataract depends on surgery.
In order to prevent diabetes or to prevent and treat complications, Korean Patent Publication No. 10-195886 discloses a formulation for lowering blood glucose levels of diabetic patients and lowers blood lipid concentrations using galenical substances, including Cordyceps sinensis, cow bezoar, Phellodendri Cortex, etc.
Accordingly, the object of the present invention is to provide Aralia extracts that are effective for preventing, delaying or treating cataract caused by high blood glucose levels.
Another object of the present invention is to provide a composition comprising another active ingredient, in addition to the Aralia extracts.
These objects of the present invention can be achieved by solvent extracts from Aralia.
The present invention provides a composition for prevention or treatment of cataract comprising solvent extracts of Aralia, wherein said solvent is ethanol, methanol or a mixture thereof.
Further, the present invention provides a process for preparing a composition for prevention and treatment of cataract, wherein the process comprises the following steps of:
a) extracting Aralia with alcohol;
b) filtrating the extract obtained from step a) to give a residue and a filtrate; and
c) removing the alcohol from the filtrate obtained from step b) to give a powder.